The long-term objective of this behavioral research program is to improve the care and management of captive chimpanzees by conducting quantitative studies of applied behavioral issues. The behavioral research incorporates novel advances in four areas of environmental improvement for chimpanzees. (1) Human-chimpanzee interactions will be evaluated as environmental enrichment using positive reinforcement training. (2) The roles of cognitive stimulation, predictability and control in chimpanzee enrichment will be measured. (3) Behavioral management techniques will be used to try to reduce the weight of obese chimpanzees, while maintaining their well-being. And (4) Problems related to managing social behavior while reducing colony production will be studied. These investigations are essential to developing valid criteria for regulating chimpanzee well-being and meeting the societal desire for improving the care of laboratory primates.